In a wireless sensor network, if neighboring nodes transmit data packets of their own at the same time, collision will occur. As shown in FIG. 1, a node A and a node C occupy identical slot to transmit data packets of their own. And as for a neighboring node B, as it receives data packets at this slot, obvious collision is produced.
Currently, in order to overcome such collision, a slot assignment method is used, so as to ensure that neighboring nodes transmit data packets of their own at different slots. As shown in FIG. 2, a node A transmits its data packets at a slot n, a node C transmits its data packets at a slot m, and as for a neighboring node B, it receives data packets transmitted by the node A and the node C at different slots. So transmission collision may be avoided, and fewer packets will be dropped, a higher delivery ratio will be achieved.
However, in the implementation of the present invention, the inventors found that the larger a network is, the more difficult the slot assignment is. Among so many nodes, for one slot, determination about which node may reserve the slot becomes more complicated, meanwhile, the negotiation overhead (for example, a size of a local table in one node and a size of a control packet) is large. How to mitigate such a problem becomes a direction of study in the industry.
It should be noted that the above description of the background art is merely provided for clear and complete explanation of the present invention and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background art of the present invention.